Metallic ore deposits
This chapter describes the metallic ore deposits of Chile, their mineralized host rocks and the processes involved in ore formation, and provides a brief overview of the mining history of this Andean copper-rich country. The ore deposits are ordered according to their respective economic importance. Thus, after mining history and a general introduction, Chilean porphyry copper–molybdenum deposits are described first, with subsequent sections dealing with epithermal precious metals, iron oxide copper–gold and iron oxide–apatite deposits, stratabound copper–(silver) ores, precious metal veins, sedimentary-hosted gold and porphyry gold deposits, skarn rock ores and, finally, an overview of metallogenic evolution.
About 40% of the known copper resources of the world occur in Chile, with the native populations using the red metal at least since 500 BC. Bracelets, earrings and weapons that have been found in archaeological sites in northern Chile were made of either native copper or copper-rich minerals that were melted in small quantities and subsequently hammered. Copper production during Spanish colonial times (1541–1810) amounted to some 80 000–85 000 tons, with high-grade oxidized copper minerals being exploited and melted with charcoal. Despite this mining activity, however, Spaniards regarded copper as ‘plebeian metal’ because of its relatively low value, and it was used mostly as ballast for ships returning to Spain, rather than for technological or industrial purposes. The colonial Spaniards were much more interested in gold and silver, and mining activities were consequently mostly orientated towards precious metals.
Prior to Spanish conquest the Incas dominated northern Chile and had already exploited
Figures & Tables
This book is the first comprehensive account in English of the geology of Chile, providing a key reference work that brings together many years of research, and written mostly by Chilean authors from various universities and other centres of research excellence. The 13 chapters begin with a general overview, followed by detailed accounts of Andean tectonostratigraphy and magmatism, the amazingly active volcanism, the world class ore deposits that have proven to be so critical to the welfare of the country, and Chilean water resources. The subject then turns to geophysics with an examination of neotectonics and earthquakes, the hazardous frequency of which is a daily fact of life for the Chilean population. There are chapters on the offshore geology and oceanography of the SE Pacific Ocean, subjects that continue to attract much research not least from those seeking to understand world climatic variations, and on late Quaternary land environments, concluding with an account examining human colonization of southernmost America.
During his voyage on H.M.S. Beagle, an extended visit to Chile (1834-35) had a profound impact on Charles Darwin, especially on his understanding of volcanoes, earthquakes and tsunamis. Over more recent decades scientists have come to recognize the Chilean Andes as providing the classic example of a mountain belt produced by oceanic subduction beneath a continent, as well as some of the most dramatic scenic and climatic variations on Earth. In the final chapter, the editors offer a description of a drive from the Mediterranean landscapes of central Chile to the hyperarid Atacama Desert, a contribution designed to give visitors a chance to experience for themselves the geology and scenery of this extraordinary country.